01-07-2025
QuickCheck: Is there a planet in our solar system that spins the wrong way?
The planet Venus is the second planet from the sun and is almost equal in size and mass with our planet, Earth. - pix by JAXA/ISAS/DARTS/Kevin M. Gill (CC BY 2.0)
PETALING JAYA: The sun rises from the east, and sets in the west - this is a well-established fact for the longest time, and this is due to Earth's rotation, which is moving from west to east on its rotation.
While planets in our solar system move one way, is it true that there's a planet moving in the opposite direction?
Verdict:
TRUE
While the other planets are rotating in the same direction, only one planet is going against the flow - and that is Venus.
The second planet from the sun, has a retrograde motion - which means that the orbital or rotational motion of Venus is going in the opposite direction on its axis.
The initial theory of why Venus does this is that it initially spun in the same direction as most other planets and it simply flipped its axis 180 degrees at some point.
Scientists have argued that the sun's gravitational pull on the planet's very dense atmosphere could have caused strong atmospheric tides.
However, in 2000, a team of scientists from the French research institute Astronomie et Systemes Dynamiques proposed a new explanation.
Scientists Alexandre Correira and Jacques Laskar suggested that Venus may not have flipped at all.
According to the report published in Nature, they propose instead that its rotation slowed to a standstill and then reversed direction.
Taking into account the factors mentioned above, as well as tidal effects from other planets, the team concluded that Venus's axis could have shifted to a variety of positions throughout the planet's evolution.
Another theory is that Venus, also known as Earth's twin planet, could have been hit by a giant asteroid, leaving it spinning the other way.
While large asteroids have hit Earth during its history (one of the theories as to how the Moon formed), it seems like a plausible idea that, during the early stages of the Solar System, Venus could have been hit by a celestial object that is similar in size to itself causing it to spin backwards.
If this collision also altered Venus' orbit, the presence of the Sun, Mercury and Earth in this solar system would have pulled its orbit back to its original position.
Another fun fact is that because of Venus' slow rotation, one Venus day is about 243 Earth days or close to eight Earth months.
With this trivia, have a good (Earth) day.
References:
1. science/venus-spins-backwards
2. article/why-venus-spins-the- wrong/